Scientists identify hundreds of chemicals from plastics in people

Hundreds of plastic-related chemicals were identified in pregnant women by scientists at UC San Francisco in a study published today in Environment & Health Journal. Alarmingly, many of these chemicals have little to no current exposure data, which means little is known about how much they are impacting people and their health.

“It is extremely disturbing to find hundreds of plastic-related chemicals for which there is little to no research about their health impacts,” said Dr. Tracey J. Woodruff, senior author and professor and director of the UC San Francisco Program on Reproductive Health and the Environment and co-director of the EaRTH Center. 

Evidence shows that chemicals in plastics can increase the risk of health harms including colon and stomach cancer, infertility, respiratory disease, neurodevelopmental problems and cancer. Meanwhile, plastic production is expected to triple by 2060, which means that exposures to these health-harming chemicals will also increase.

There are at least 10,000 chemicals used in plastics or in the production of plastics, some of which have sufficient data to identify that they are toxic to reproduction and human development. However, for most of these, there is little data on either exposures or health effects in people, particularly for the susceptible prenatal period, according to the researchers.

Meanwhile, only 400 chemicals are measured in people’s bodies by the CDC’s National Health and Nutrition Examination Survey (NHANES) using traditional targeted methods. UC San Francisco scientists used non-targeted analysis using “high-resolution mass spectrometry (HRMS), which is able to scan for hundreds of thousands of chemical features in a single run, expanding the chemical coverage beyond the targeted analysis of priority pollutants.”

Of the chemicals researchers identified, more than half (230 out of 441) were not previously reported in the Blood Exposome Database, and 398 were not documented in the Exposome Explorer Database. Scientists and the Environmental Protection Agency rely on these and other databases to track chemical use and known health impacts. Nearly half (45%) are involved in polymer or plastics production or qualify as high volume production chemicals, while production volumes are unknown for nearly one third (29%).

Nine of the plastic-related chemicals researchers identified, including two PFAS, have multiple uses, are high production volume chemicals, and yet there is little to no health impacts research on three of them: 1,3-Diphenylguanidine (used in tires, flooring, condoms), undecanedioic acid (uses include lubricants, cosmetics, pharmaceuticals), and 1-Octyl-2-pyrrolidone (uses include cleaners, inks, and agricultural products).

“It is a real concern that we are exposing people to high production volume plastic chemicals that we know little about,” said Junjie Yang, PhD, a Postdoctoral Scientist with the UC San Francisco Program on Reproductive Health and the Environment. “And some of the chemicals we identified in pregnant women are linked to health harms for pregnant women and children.”

For example, the study shows that multiple plastic-related chemicals were associated with increased risk of preterm birth, including acetyl tributyl citrate, a plasticizer often a replacement for phthalates which is found in food packaging, toys, medical devices, and cosmetics; diisobutyl phthalate, another plasticizer found in PVC plastics, inks, coatings, adhesives, and some rubber products; and 8-hydroxyquinoline, which is used in many ways, including as a pesticide and fungicide, antiseptic, or corrosion inhibitor. Undecanedioic acid (used in polyesters, adhesives, lubricants, and cosmetics, among others) was associated with increased risk of gestational diabetes. Additional suspect chemicals were identified that were higher in pregnant women giving birth preterm and with GDM.

“People are being exposed to thousands of chemicals not only as plastic production and use increases, but as plastics break down and toxic chemicals get released into people and the environment,” said Dr. Woodruff. “Microplastics and nanoplastics are being found in nearly every part of the human body and every corner of the earth. It is abundantly clear that the health impacts of this plastic contamination can no longer be ignored.”